In the field of medicine, there is a growing need for three-dimensional visualization of affected parts and/or specific body parts in the processes of, for example, informed consent, decision on courses of treatment, medical education, and medical research. In particular, in the case of three-dimensional visualization utilizing a three-dimensional molded model, not only the sense of vision but also the sense of touch of the actual three-dimensional geometry allows transmission of a large amount of information that cannot be transmitted completely through computer images.
There has conventionally been known creating three-dimensional geometry data using DICOM (Digital Imaging and Communications in Medicine), a standard for medical diagnostic apparatuses such as X-ray CT and MRI (Magnetic Resonance Imaging), and based on the data, producing a three-dimensional molded model for medical use rapidly and precisely with a plaster-based material using a powder-laminating molding machine.
There have, however, been problems that the softness of complex organs, such as a liver, having an internal structure cannot be simulated and that information on the feeling of touch of an organ or the like cannot be provided to doctors and/or nurses handling organs, etc.
Combinations and collaborations between medical services and engineering having been rapidly developing, there has recently been proposed a simulator program utilizing an advanced engineering calculation method. The simulator program is arranged to reconstruct body parts to be operated polygonally on a computer screen to simulate the surface of an organ such as a liver.
Meanwhile, there has been known a three-dimensional printer with which a three-dimensional molded model using hard and flexible resins having their respective different mechanical properties can be produced by simultaneously forming jets of the resins and combining them. With such a three-dimensional printer, it is possible to reproduce not only the surface but also the internal structure of the target form structure. However, there are only a few such printers that can reproduce the flexibility of complex organs, such as a liver, having an internal structure or the hardness of bones and the like.
As a related art, there has been proposed a three-dimensional molded object production method with which a multi-color and multi-material three-dimensional object having a complex structure and also having different hardness at different parts thereof can be molded by holding and fixing multiple types of model materials in one layer at their respective molding positions in a holder sheet having a web structure in which molding model materials can be held, placing a next-layer holder sheet on the fixed layer of the model materials, holding and fixing multiple types of next-layer model materials at their respective molding positions in the next-layer holder sheet, repeating fixing model materials sequentially to upper layers, and after laminating the layers, solving and removing the holder sheets (see Patent Document 1). However, the method disclosed in Patent Document 1 requires hard or soft model materials so that different parts have different hardness accordingly.    [Patent Document 1] WO2005/037529